<pubnumber>908R11003</pubnumber>
<title>Investigating Rare Earth Element Mine Development in EPA Region 8 and Potential Environmental Impacts</title>
<pages>35</pages>
<pubyear>2011</pubyear>
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<abstract></abstract>
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<scandate>01/02/13</scandate>
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Investigating Rare Earth Element Mine
Development in EPA Region 8 and Potential
Environmental Impacts
Justin Paul
Greater Research Opportunity Fellow
Gwenette Campbell
Region 8 Mining Team Coordinator
Additional review by Region 8 Mining Team Members
August 15, 2011
EPA Document-908Rl 1003
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Report Index
1.0 Abstract 3
2.0 Background 3
2.1 Defining Rare Earth Elements 3
2.2 Defining Key and Critical Materials 4
2.3 Uses 4
2.4 Supply 5
3.0 Active Exploration and Deposits in Region 8 6
3.1 Bear Lodge 7
3.2 Iron Hill 9
3.3 Wet Mountains 9
3.4 Lemhi Pass 10
3.5 Sheep Creek 10
4.0 Mining and Refining Processes //
5.0 Geochemistry and Possible Contaminants 12
6.0 Potential Risks to Human Health and the Environment 14
6.1 China 14
6.2 Radionuclides 15
6.3 Rare Earth Elements 15
6.4 Metals 15
6.5 Mountain Pass Legacy 18
6.6 Bear Lodge Case Study 18
7.0 Conclusions 20
8.0 References 22
9.0 Appendix 24
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1.0 Abstract
Even though most people have not heard of rare earth elements, they govern man kind's modern
lifestyle. The 17 periodic elements receiving rare earth designation encompass nearly all electronic, clean
energy, and military technologies due to their unique physical and chemical properties. Despite world-wide
usage of these elements, China succeeded in monopolizing the rare earth element industry two decades ago. Use
of these elements has risen exponentially, while China has slashed rare earth element exports driving prices to
record highs. The United States government has been reviewing the risks associated with rare earth element
supply disruption due to their importance in modern technologies vital to economic growth and national
defense. This prompted the U.S. Department of Energy (USDOE) to identify "key" and "critical" materials.
Many of the key and critical materials are rare earth elements. The USDOE has even developed a strategic plan
to achieve a globally diverse supply of these materials. This includes developing the United State's rare earth
element resources.
Such a strategic plan, coupled with record high prices, has implications for Region 8 of the
Environmental Protection Agency (Region 8), which is relatively enriched in economic occurrences of rare
earth element minerals. Exploration activities and preliminary mining procedures indicate the real possibility of
rare earth element mining within Region 8 at the Bear Lodge property of northeastern Wyoming within five
years. Oversight of rare earth element production represents new challenges for government agencies, including
Region 8, considering the lack of experience in dealing with these operations. If best management practices
(BMP) are not used and/or operations are not carefully monitored, rare earth element production may put
human health and the environment at risk. This comprehensive report strives to inform readers of all pertinent
background information surrounding the rare earth element market, active exploration and deposits within
Region 8, mining and refining processes, possible contaminants, and the potential risks for human health and
the environment.
2.0 Background
2.1 Defining Rare Earth Elements
Rare earth elements represent the 15 periodic elements of the lanthanide family, which reside at the
bottom of the periodic table in the top horizontal row of the f-block elements (Figure 1). Scandium and yttrium
are also considered rare earth elements because they exhibit similar properties to the lanthanide family. Rare
earth elements, sometimes referred to as rare earths or REE, can be further classified as "light" or "heavy"
based on their relative atomic weights. The light rare earth elements include lanthanum, cerium, praseodymium,
neodymium, promethium, samarium, and europium, while heavy rare earth elements describe gadolinium,
terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium (Figure 2).
According to the Institute for the Analysis of Global Security (IAGS), such distinctions are important
considering light rare earth elements account for higher concentrations globally than heavy rare earth elements
(IAGS, 2010).
The "rare earth" designation inaccurately portrays the likelihood of the 17 rare earth elements' natural
occurrence. Rare earth elements are actually lithophile, meaning they are enriched in the Earth's crust. In fact,
most rare earth elements exist in the Earth's crust in higher concentrations globally than silver or mercury
(Castor and Hedrick, 2006). Rare earth elements are generally evenly concentrated throughout the Earth's crust
resulting in few locations around the globe where they can be economically mined. The lack of rare earth
element mines has the potential to create serious supply issues for these elements vital to electronic, clean
energy, and military technologies (IAGS, 2010).
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2.2 Defining Key and Critical Materials
In 2010, the USDOE identified "key" and "critical" materials. These materials are a collection of
periodic elements, most of which are rare earth elements, vital to the economic growth and national security of
the United States. For the purposes of this report, key materials and critical materials will be referred to as "key
elements" and "critical elements" to clarify what these materials truly are. The distinction between key and
critical elements is subtle yet important. Both key and critical elements are widely used in electronic, clean
energy, or military technologies and both have supply risks; however, critical elements are essential to the
production of clean energy technologies and have even greater supply risks associated with them than key
elements. The supply risks result from a small global market, lack of supply diversity, and market complexities
caused by coproduction and geopolitical risks associated these elements (USDOE, 2010).
The USDOE (2010) determined there to be 14 key elements (Figure 3). Within the group of 17 rare
earth elements, nine of which received key element distinction. These rare earth elements include lanthanum,
cerium, praseodymium, neodymium, samarium, europium, terbium, dysprosium, and yttrium. Five other
periodic elements were labeled key elements as well. The five other periodic elements include lithium, cobalt,
gallium, indium, and tellurium (USDOE, 2010).
The United States is currently experiencing a great increase in clean energy technology development.
The same can be said for electronic and military technologies too, and these trends are expected to continue into
the future. The USDOE was concerned the rising demand for key elements in electronic and military sectors
could hamper the growth of the U.S. "green economy, " or an economy based on renewable energy. The
USDOE (2010) conducted a further assessment on the 14 key elements to determine how "critical" these
elements are to the development of the United States green economy in the short (0-5 years) and medium (5-15
years) term. The assessment was solely based on each key element's importance to the development of the
green economy, the summation of supply risks, and the increasing demand for these elements in the electronic
and military technology sectors. The USDOE (2010) rated dysprosium, neodymium, terbium, europium,
yttrium, and indium critical in the short term. Dysprosium, neodymium, terbium, europium, and yttrium, all of
which are rare earth elements, received critical designation in the medium term (USDOE, 2010).
For the remainder of this report, the key and critical elements will collectively be referred to as rare
earths. However, it is important to note that lithium, cobalt, gallium, indium, and tellurium are not actually rare
earth elements. The terms key and critical elements may still be used when specifically referring to elements
receiving key or critical designation.
2.3 Uses
Rare earths comprise an enormous array of technological applications and are becoming widely used
due to their unique catalyst, magnetic, and optical properties. For example, all cell phones and laptops contain
rare earths. As developed nations modernize and transition to green economies, rare earth consumption for
clean energy applications will become an ever increasing phenomenon and vital to successful conversions from
traditional industrial economies. Such modern and clean energy technologies govern today's societies to the
extent experts consider rare earth usage significant economic indicators (Castor and Hedrick, 2006).
Permanent magnets represent the staple clean energy technology of future green economies. They
constitute main components of lightweight, high powered motors and generators due to their production of a
stable magnetic field without the need for an external power source. Permanent magnet motors power
contemporary electric, hybrid electric, and plug-in hybrid electric vehicles, while permanent magnet generators
produce electricity from wind turbines (USDOE, 2010). The key element derived samarium-cobalt permanent
magnets dominate rare earth technology because they produce a magnetic field in a much smaller size. The
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samarium-cobalt permanent magnet also retains its magnetic strength at high temperatures making it ideal for
clean energy and even military applications, including precision guided munitions and aircrafts (IAGS, 2010).
Permanent magnets work in conjunction with high efficiency rare earth based batteries to store energy in
electric, hybrid electric, and plug-in hybrid electric vehicles (USDOE, 2010). Current generation hybrid electric
vehicles use a battery with a cathode containing a host of rare earths including lanthanum, cerium, neodymium,
praseodymium, and cobalt (Kopera, 2004). Each hybrid electric battery may contain several kilograms of rare
earth materials (USDOE, 2010). Plug-in hybrid and electric vehicles require even greater storage capacity and
higher power ratings than typical hybrid vehicles. In light of this, automakers will likely use the lithium ion
battery, increasing demand for yet another key element. Scientists at the Argonne National Laboratory
estimated one lithium ion battery contains 3.4-12.7 kilograms of lithium depending on proprietary design
(USDOE, 2010).
Perhaps the fastest growing consumer of rare earth material is the phosphor production industry. In
2008, phosphors alone accounted for 7% of all rare earth usage by volume and 32% of total rare earth value.
Phosphor materials produce luminescence essential to today's lighting technologies. Older generation
fluorescent lighting used no rare earths, but rare earths make current fluorescent lighting phosphors more
efficient and visually pleasing. Specific rare earths responsible for this include lanthanum, cerium, europium,
terbium, and yttrium. Fluorescent lighting phosphor usage is expected to rise by 230% over current levels due to
USDOE mandating increased efficiency ratings. Mass quantities of similar phosphor materials are produced for
application in television screens, computer monitors, and electronic instrumentation, increasing demand for rare
earth based phosphors (USDOE, 2010).
The clean energy technologies discussed to this point are expected to drive the U.S green economy in
the short and medium term. Other clean energy applications using rare earth materials include grid storage
batteries, fuel cells, nuclear power, electric bicycles, magnetic refrigeration, fluid cracking catalysts, and
automotive catalytic converters. Despite the wide spread usage of rare earths in the clean energy sector, the
largest user of rare earths remains the electronics sector. Rare earths are used in nearly all electronic device
produced, ranging from iPods to calculators. The importance of rare earths to the military sector cannot be
forgotten either. The United States military incorporates rare earths into many different technologies from
guidance systems to night-vision goggles. Increasing implementation of rare earth materials will further strain
an already fragile supply chain responsible for providing adequate amounts of rare earth materials to
international electronic, clean energy, and defense technology sectors; all of which increase the overall supply
concerns associated with rare earths (USDOE, 2010).
2.4 Supply
The bulk amount of rare earths needed globally per year remains small relative to other industrial
materials; however, the rare earth supply chain recently developed larger, more internationally complex issues
than other industrial materials. To fully understand the issues at hand, one must first understand the evolution of
the rare earth element industry over the past 50 years. From 1965-1985, the United States was the major
producer of rare earth elements until the Mountain Pass mine in southeastern California (Figure 4) ceased
mining operations due to China flooding the market with low cost rare earth elements (Castor and Hedrick,
2006). Soon thereafter, China emerged as the main producer of rare earth elements and holds that title today
with 95% of production in their control (USGS, 2010). The unparalleled Chinese dominance of the rare earth
element market transpired because of their large, high quality reserves, coupled with minimal capital
investment, low labor costs, and lack of environmental regulation (IAGS, 2010).
Even though China controls 95% of rare earth element production, they only possess 36% of identified
global reserves (USGS, 2010). In recent years Chinese government officials realized rare earth elements are of,
"urgent need of protection and utilization," and they must "protect and make rational use of China's superior
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natural resources." As a result, China restricted rare earth element exports, closed down smaller mining
operations, consolidated larger ones, and stockpiled rare earth elements. In 2010, China restricted exports of
dysprosium, terbium, thulium, lutetium, yttrium, gadolinium, holmium, erbium, and ytterbium (IAGS, 2010).
This resulted in a 40% overall reduction of rare earth element exports from 2009 (USDOE, 2010).
Increased demand coupled with limited exports caused dramatic price increases of individual rare earth
element oxides over the past two years. In July 2010, neodymium oxide cost $108 U.S. dollars per kilogram,
but a year later in July 2011 the same neodymium oxide was selling for $245 U.S. dollars per kilogram. This
represents a 226% price increase in one year. Similarly, the price of dysprosium oxide increased 200% in one
year with one kilogram of dysprosium oxide now costing $1,200 U.S. dollars (mineralprices.com). These price
trends can be observed with nearly all rare earth elements and prices are not expected to go down in the near
future.
At the heart of these issues remains finding economical rare earth element occurrences and developing
them into a profitable operation is difficult. The three main criteria in determining economic feasibility of a
potential rare earth element mine include tonnage, grade, and the cost of refining rare earth minerals into useful
materials for industry (USDOE, 2010). Rare earth element mine capacity and expansion lag behind increasing
international demand for rare earth elements. Various deposits exist around the world (Figure 5), but estimates
suggest an operational mine takes 2-10 years to begin production without any unforeseen setbacks (IAGS,
2010). During this time, continued exploration, process development, feasibility studies, permitting,
construction, and commissioning must take place (USGS, 2010).
The United States government is concerned about rare earth supply. The U.S. Department of Defense
(USDOD) has special interest in maintaining a steady rare earth supply considering usage of these elements in
various military technologies. The USDOE remains concerned over rare earth supply because these elements'
necessity for producing clean energy technologies. In light if this, the United States government realized swift
and strategic measures were needed to secure a long lasting rare earth supply chain. In 2010, the U.S
Department of Energy received funding from Congress to develop a strategic plan to mitigate supply risks and
place the U.S. green economy on a reliable and sustainable pathway. One aspect of the plan strives to improve
recycling, reuse, and efficient use of critical elements. Such actions serve to stabilize the rare earth market in
times of undersupply. Another point of the strategic plan declares appropriate rare earth substitutes must be
identified to lessen the Chinese dependence of rare earth elements (USDOE, 2010). This could be accomplished
by congressional and military commands placing more emphasis on education and awareness of rare earth
(IAGS, 2010). Finally, the cornerstone of the plan stresses a globally diverse supply of rare earths is needed
(USDOE, 2010). The Institute for the Analysis of Global Security suggests the United States should pursue rare
earth mine ventures with nations of known reserves to increase the number of supply lines. Developing a
diverse supply also means utilizing the United States' substantial reserves of rare earth elements. The United
States is committed to nurturing the development of rare earth element mining in America by providing
assistance and research collaboration when needed (IAGS, 2010). Such a strategic plan puts Region 8 in the
middle of an American mining revolution.
3.0 Active Exploration and Deposits in Region 8
Even though rare earth elements are overall evenly concentrated throughout the Earth's crust, a wide
range of geologic conditions are favorable for rare earth element enrichment. In fact, the United States
Geological Survey (2010) has identified 29 "principle," or large, rare earth element deposits within the United
States (Figure 6). Placers, iron ores, and alkaline igneous complexes constitute the major types of rare earth
element deposits in the U.S. These deposits account for 13% of the world's identified rare earth element
reserves and have the potential to supply the United States of its rare earth element needs for decades to come.
Although the United States displays significant reserves, no rare earth element mines currently operate in
America. The mine closest to rare earth element production is the Mountain Pass mine in California (Region 9),
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which plans to resume mining operations by 2012 after modernization of production facilities are completed.
Many of the principle rare earth deposits in the United States, such as the Bokan Mountains in Alaska, Diamond
Creek in Idaho, and the Bear Lodge Mountains in Wyoming, are now actively being explored for their mining
potential in light of record high rare earth element prices (USGS, 2010).
Only three of the 29 principle rare earth element deposits reside within Region 8. With this said, Region
8 may seem to be an insignificant rare earth element stakeholder; however, Region 8 will most likely host the
second operational rare earth element mine in the United States, a mine that could quite possibly become the
largest rare earth element producer in America. In addition to the three principle rare earth element deposits, the
USGS (2000) determined there to be over 10 rare earth element occurrences within Region 8. Record high rare
earth element prices have resulted in a rare earth "ramp up" throughout Region 8. The focus of this next section
will be on the exploration and resource potential of the three principle rare earth element deposits in Region 8,
but it is important to note if China continues to cut exports and U.S. rare earth element demands are not met by
other international suppliers, prices could rise to the extent even the minor rare earth element occurrences could
be actively explored and mined in the future.
3.1 Bear Lodge
The Bear Lodge deposit has the most potential for rare earth element mining to develop in Region 8.
The deposit is located approximately six miles northwest of the town of Sundance in northeastern Wyoming.
The Bear Lodge property itself lies within the Bear Lodge Mountains in the Black Hills National Forest (Figure
7). Rare earth element mineralization was first discovered at the Bear Lodge property in 1949 by geologists in
search of uranium. Significant amounts of uranium were never found on the property, but interest in rare earth
elements soon generated over the Duval Corporation's discovery of high grade rare earth element oxides in
1972 (USGS, 1983). Other exploration companies have found multiple high grade areas over the past 40 years
increasing the potential for mining. Even though high grade rare earth element oxides were known to exist on
the property, prices were not high enough to warrant mining activities. With prices higher than ever, rare earth
element mining will most likely be a reality at the Bear Lodge property within the next five years.
Rare Element Resources Inc., a Wyoming cooperation based in Colorado, is poised to develop the Bear
Lodge property into a world-class rare earth element mine. The company bought 100% ownership in the
property comprising 90 unpatented federal lode claims and one state lease for a total of about 2,400 acres. Rare
Element Resources began actively exploring the property for high grade rare earth element mineralization in
2004. Core drilling, geochemical analysis, and remote sensing techniques over the past six years have helped
the company better understand the local geology and upgrade the resource reserve status. Spring 2011 National
Instrument (NI) 43-101 results, which establish guidelines for companies trading in the Canadian stock
exchange to disclose mineral resources to the public, increased the indicated rare earth element resources by 4.9
million tons, which now totals over 17 million tons of rare earth oxides grading at 3.46% (Rare Element
Resources, 2011). Light rare earth elements account for much of the indicated resources at the Bear Lodge
property (Pickarts, 2011). With additional drilling, it is thought that the Bear Lodge reserves could match or
even out produce the Mountain Pass mine in California (Rare Element Resources, 2011).
The rare earth element resource at the Bear Lodge deposit is mainly found in a rare type of igneous rock
called carbonatite (Figure 8). Carbonatites are characterized by containing 50% or more carbonate (COs2")
minerals (USGS, 1983). Exotic carbonate minerals, such as bastnasite and ancylite, have rare earth elements in
their crystal structure resulting in rare earth element enrichment of carbonatite rocks. Rare earth elements
possess the same electrical charge and similar ionic radii's allowing for their wide spread substitution within a
crystal lattice. This substitution explains why rare earth elements can be found throughout the Earth's crust and
why many different rare earth elements occur within a single mineral (Castor and Hedrick, 2006). The greatest
concentrations of rare earth element bearing minerals are generally found in carbonatite dikes, or sheet-like
vertical rock structures, surrounding an alkaline igneous complex. This holds true at the Bear Lodge deposit.
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Bear Lodge dike formation occurred when magmas enriched in alkaline materials intruded, or cross-cut, the
existing rock 38 to 60.5 million years ago. The intrusions are responsible for what the USGS has described as
the largest rare earth element deposit in North America (USGS, 1983).
Rare Element Resources is interested in developing three separate locations at the Bear Lodge property
near the area known as "Bull Hill" (Figure 9). Two of the three locations, "Bull Hill southwest" and "Bull Hill
northwest," are known to have numerous carbonatite dikes present with some over 1,000 feet long and hundreds
feet wide. Three separate mineralogical zones are present in these carbonatite dikes (Figure 10). Each
mineralogical zone is defined by depth and the degree of weathering experienced by the dike. The carbonatite
dikes are highly weathered near the surface into what the company refers to as an "iron oxide-magnesium
oxide-rare earth zone" or "FMR" (Pickarts, 2011) (Figure 11). Weathering served to economically concentrate
the rare earth element minerals (USGS, 2010). The loose, friable character and fine grain nature of rare earth
element bearing minerals in the FMR allow a 90% recovery with a 19% rare earth element oxide grade by
employing simple crushing, scrubbing, and screening processes. Chemical processing will be accomplished at
an off-site facility (Pickarts, 2011).
Below the FMR zone, an incompletely weathered "carbonatite-oxide" mineralogical zone exists. Rare
Element Resources plans to mine this bastnasite rich zone that extends hundreds of feet in the subsurface
(Pickarts, 2011). The oxide material displayed favorable recovery in previous metallurgical testing (Rare
Element Resources, 2011). The carbonatite-oxide zone of the dikes is also of mining interest because it is
characterized by an absence of sulfides minerals. However, sulfides are found below the carbonatite-oxide zone
in what Rare Element Resources terms the "transitional zone" and below (Pickarts, 2011). The transitional zone
is described as a relatively flat-lying, thin layer where weathering has leached sulfides into a mixed carbonatite
oxide-sulfide zone (Rare Element Resources, 2011). Below the transitional zone is an unoxidized carbonatite
zone that contains all its original sulfide content. Rare Element Resources has no recovery plan for rare earth
element bearing minerals found in this sulfide zone (Pickarts, 2011). Identifying the sulfide bearing geology is
important because of potential acid mine drainage concerns at the mine.
The "Bull Hill southwest" location contains a large portion of the rare earth element resource where a
dominant dike set and several minor dike sets are present. "Bull Hill northwest" displays similar characteristics
to the "Bull Hill southwest" location. The third location, "Whitetail Ridge," shows FMR stockwork, or rocks
cut by a network of smaller mineralized dikes, near the surface. The stockwork displays low rare earth element
oxide grades compared to the dikes. Stockwork zones grade between .5% and 2% rare earth element oxide,
while FMR zones can grade close to 20% rare earth element oxide. Rare Element Resources is developing low
cost physical processing methods to make stockwork more economical to mine (Pickarts, 2011).
Don Ranta, president of Rare Element Resources, has been quoted as saying, "the Bear Lodge project is
advancing rapidly." Rare Element Resources hopes to complete a pre-economic feasibility study by the first
quarter of 2012 (Rare Element Resources, 2011). Metallurgical testing of mineralized core samples will
continue throughout 2011 as will the design of their commercial processing (Rare Element Resources, 2011).
The company plans to submit a Plan of Operation, or POO, to the United States Forest Service Sundance office
by early 2012. The USFS will then have 30 days to accept or reject the POO. Modifications to the POO will
incorporate comments received from the USFS (Pickarts, 2011). District Ranger Steve Kozel at the Sundance
USFS office explained the USFS will not prohibit mining at Bear Lodge but will ensure mining and on-site
processing are done so in an environmentally conscious manner. The National Environmental Policy Act
(NEPA) process will be initiated by the USFS once the POO is accepted (Kozel, 2011). An EIS will then be
developed and made available for EPA and public review.
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3.2 Iron Hill
A smaller, yet still significant, Region 8 rare earth element deposit is known as Iron Hill. The Iron Hill
deposit is located about 30 miles southwest of Gunnison in southwestern Colorado (Figure 12). A previously
explored section of the deposit is near a community center and several houses. This deposit is underlain by
carbonatite similar to the Bear Lodge deposit in Wyoming. The core of the Iron Hill deposit contains a massive
plug, or neck, of carbonatite enriched in rare earth elements, niobium, thorium, and titanium. An adjacent
igneous rock unit possesses rare earth elements too (USGS, 2010). Staatz and other (1979) calculated the Iron
Hill deposit to contain nearly 2.9 million tons of rare earth element oxides, although Armbrustmacher (1983)
found the carbonatite to only grade at an average of 0.5% rare earth element oxide. This grade is too low at the
current time for economically feasible rare earth element production. Rare earth element oxide grades need to
be at 2.5% or higher to be economically mined (Pickarts, 2011). However, some carbonatite dikes at Iron Hill
studied by Olsen and Hedlund (1981) contain up to 3% rare earth element oxide, which are more attractive to
mining companies.
The Iron Hill deposit is mainly known for its substantial titanium resources (USGS, 2010). Van Gosen
and Lowers (2007) describe the Iron Hill deposit as the largest titanium resource in the United States. Teck
Resources Inc. bought many of the patented claims within the Iron Hill deposit in 1990. The mining company's
interest in the property resides in the substantial titanium resources, not the rare earth elements. No mineral
resources have been produced to date, and Teck Resources is not actively conducting work at the Iron Hill
property.
Environmental concerns regarding thorium and asbestiform mineral content could create expensive
waste disposal measures to ensure these materials are handled in an environmentally friendly manner. The low
rare earth oxide grades and immense investments needed for infrastructure development explain why Teck
Resources has little interest in mining rare earth elements at the property. At this time, the company would not
be able to compete with established rare earth element mines such as Molycorp's Mountain Pass mine in
California (Van Gosen, 2011). For these reasons, it does not appear rare earth element mining will take place at
Iron Hill in the near future. Although as with many rare earth element deposits, multiple mineral resources
could be concurrently extracted at the Iron Hill property, which increases mining potential. A well coordinated
mine and mill plan could make this realization possible (USGS, 2010). If rare earth element prices continue to
rise and low grade rare earth element oxide recovery methods are developed, Iron Hill may be thoroughly
explored for rare earth elements and subsequently mined in the future.
3.3 Wet Mountains
The third principle rare earth element deposit in Region 8 is the Wet Mountains deposit in the
surrounding areas of Freemont and Custer counties in south-central Colorado (Figure 13). Multiple alkaline
complexes formed in the area 500 million year ago during the cooling of the intrusive magmas. The deposit
shows proven niobium, rare earth elements, and thorium resources. Niobium, rare earth element, and thorium
mineralization can be found in the minerals ancylite, bastnaesite, monazite, synchysite, and thorite. The mineral
resources are mainly found in quartz veins with lesser amounts in carbonatite dikes and fracture zones (Figure
14). Fracture zones and veins in the area have the highest economic potential for rare earth element recovery
(USGS, 2010).
The USGS (1988) studied the Wet Mountain area extensively to determine the potential rare earth
element resources in the area. The study even determined the light and heavy rare earth element fractions in the
area. Potential light and heavy rare earth resources totaled 73,270 and 48,850 tons respectively with an average
rare earth element oxide grade of 2.15%. Despite rare earth oxide grades close to economical percentages,
mining seems unlikely due to land issues. Many of the fracture zones and veins reside on private land. Also
inhibiting mining is the nature of the veins that contain the rare earth element minerals. The veins are not large
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10
and can extend long distances in the subsurface. These vein characteristics make mining costly. In addition, the
thorium content of the mineralized veins could require expensive disposal (Van Gosen, 2011).
3.4 Lemhi Pass
The Lemhi Pass deposit resides in the central Beaverhead Mountains on the borders of Idaho and
Montana a few miles away from Tendoy, Idaho. Even though nearly the entire deposit lies on Idaho state land,
Region 8 should be aware of the deposit's existence and the issues surrounding the land because some of the
area drains into Montana (Figure 15). Many parallels can be seen between Lemhi Pass and the Wet Mountains
deposits. Both display the same general geology with thorium and rare earth element resources residing in
numerous mineralized quartz veins (USGS, 2010) (Figure 16). Staatz (1972) and Staatz and others (1979)
mapped over 200 mineralized veins in the district. These mineralized veins vary greatly in size from 1 to 1,325
meters in length and from a few centimeters up to 12 meters wide. The rare earth element oxide grades of the
veins vary greatly as well. Samples from 31 mineralized veins showed rare earth element oxide grades between
.073% and 2.20% (Staatz, 1972).
Despite some rare earth element oxide grades close to economical percentages, the overall grade average
at Lemhi Pass was only .428% leaving little potential for mining (USGS, 2010). Thorium and land-use issues at
Lemhi Pass inhibit the possibilities of mining similar to the Wet Mountains (Van Gosen, 2011). Lemhi Pass is
more renowned for its thorium resources than rare earth element content. The area holds the largest thorium
resource in the United States (Van Gosen and others, 2009). Previous exploration over the past decade has
focused strictly on thorium targets by Thorium Energy Inc. (USGS, 2010).
The rare earth element resources at Lemhi Pass are in demand and very valuable. No thorium or rare
earth elements have been produced at Lemhi Pass to date, although certain aspects of the deposit remain
attractive to mining companies. Coproduction of thorium and rare earth elements cannot be ruled out. Also, the
veins display unusual middle and heavy rare earth element enrichment with especially high neodymium
enrichment (Staatz, 1972). Neodymium and other middle rare earth elements are classified under the USDOE's
list of short and medium term key materials, while the heavy rare earth elements remain some of the most
expensive rare earth products. Favorable market conditions may interest mining companies in reevaluating the
rare earth element mining potential at Lemhi Pass. Additional exploration would be needed in the area to better
define the total resources (USGS, 2010).
3.5 Sheep Creek
Each location discussed to this point was strictly a rare earth element deposit. The Sheep Creek deposit,
which is located in central Montana approximately 60 miles south of Great Falls, does not contain rare earth
elements but rather the key element cobalt (Figure 17). Mineral resources occur in extensive shale and bedded,
or horizontally layered, zones (Figure 18). These zones can be found in multiple levels throughout 2,400 feet of
rock. Some of the mineralized zones display long lateral extent in the subsurface and thicknesses of over 300
feet. Copper is the dominant metal found in the mineralized zones with the sulfide mineral chalcopyrite bearing
the copper resources in its crystal lattice (Tintina Resources, 2011). Cobalt exists as a lining on the chalcopyrite
(McCulloch, 2011).
A joint venture by Cominco and BHP explored the property in the 1980's. Tintina Resources now owns
the property, which consists of long-term leases totaling nearly 6,000 acres on private ranch lands and federal
mining claims. They have continued exploring and outlined an inferred resource of a mineralized zone near the
surface. This mineralized zone is referred to as the "Upper Copper Zone" and totaled over 7 million tons of ore
with a 2.4% and 0.12% grade of copper and cobalt respectively. The company is continuing to drill and expand
the resource at additional areas of the property (Tintina Resources, 2011).
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The large vertical, yet separated extent of the mineralized zones could lead to both surface and
underground mining activities at the Sheep Creek property. Cobalt would be coproduced from the copper rich
ores, although cobalt recovery would be difficult. Tintina Resources may only be able to extract 25% of the
cobalt lining from the chalcopyrite (McCulloch, 2011). Feasibility studies need completed to see if cobalt can
be economically produced from the copper rich ores. If cobalt prices continue to rise, this is a good possibility
in the future.
4.0 Mining and Refining Processes
Each rare earth element body is unique and requires deposit specific processing (USGS, 2010). If
substantial rare earth element resources are discovered in a location, extensive analytical analysis of the
deposit's chemical composition is conducted to determine the rare earth element bearing minerals and
individual rare earth element content. Analysis of this type is essential in determining the deposit's profitability.
Such analysis also determines how the ore will be processed and how difficult it will be to separate the
individual rare earth elements from each other (Castor and Hedrick, 2006). Production costs vary from deposit
to deposit based on the ore content and rare earth element mineralogy (USDOE, 2010). If the results of the
studies show potential for profit, advancements towards mining operations can occur. Some of these
advancements include mine plan development, pilot plant metallurgical testing, permit applications, and
conducting economic feasibility studies (USGS, 2010).
The Mountain Pass mine remains the only rare earth element mine ever to be developed in the United
States. Much of the knowledge surrounding rare earth element mining resulted from observing operations at
Mountain Pass (Castor and Hedrick, 2006). Carbonatite dikes hold the rare earth element resource similar to the
Bear Lodge deposit. Molycorp used open-pit mining to extract the rare earth element bearing mineral bastnasite
(Figure 19). In order to extract the bastnaesite at the Mountain Pass mine, heavy equipment excavated an open
pit to a depth of about 400 feet (USGS, 2010).
Rare Element Resources is proposing the same kind of mining procedures at the Bear Lodge property.
Specifically, the company plans to mine rare earth element bearing minerals down to depths of about 500 feet.
The weak nature of the rocks does not allow for the possibility of underground mining. If geologic conditions
allow, minerals may be extracted even deeper until the company comes within 30 feet of reaching the deep
sulfide rich zone. This leaves a carbonate rich reaction front in place to ensure an acidic pit lake does not
develop (Pickarts, 2011).
Extracting the ore from the Earth represents only a small portion of rare earth element production.
Refining rare earth element bearing minerals into marketable products constitutes the major aspect of rare earth
element production. Rare earth element bearing minerals may contain as many as 17 individual rare earth
elements, where each must be refined and separated into their respective products. Separation may involve
dozens of chemical processes to differentiate rare earth elements from one another and remove impurities.
These processes can make rare earth element recovery much more expensive than other metals. In light of this,
rare earth elements are often produced as byproducts or coproducts of other mineral commodities. The USGS
estimates 44% of current global rare earth element production results from byproduction (USGS, 2010).
Past refining techniques at Mountain Pass facilities provide the model for processing bastnaesite into a
rare earth element product (Figure 20). The first step of the refining process at Mountain Pass involved
removing bastnasite out of the ore by crushing the rock into gravel size fractions and then further reducing the
ore into smaller fractions via grinding (Castor and Hedrick, 2006). Once the rare earth element ore was reduced
to a smaller size, the different mineral constituents in the ore could be separated from one another using
"floatation." This was very important considering many minerals of little or no value exist in the ore. The
flotation process at Mountain Pass involved adding an agent to a vat of bastnasite slurry where air bubbles were
introduced through the bottom of the large container. Bastnasite bonded to the surfacing air bubbles and simply
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floated to the top of the container where it could be collected as froth (IAGS, 2010). Flotation at Mountain Pass
resulted in a bastnaesite concentrate yielding a 60% rare earth element oxide product. The rare earth element
oxide product would have undergone additional chemical processing in order to isolate the individual rare earth
elements. Acid was employed at the facility to dissolve the trivalent rare earth elements and various solvent
extraction steps served to separate the individual rare earth elements. After the elements were separated into
their respective oxides, they were dried, stored, and shipped for further processing into alloys or other
applications discussed earlier. The process took about 10 days from the time the ores were mined until the
separate rare earth oxides were produced (IAGS, 2010). This process will be modernized when the mine
reopens in 2012.
Even though Rare Element Resources will refine the same rare earth element bearing mineral as
Molycorp, a different refining process will most likely be used to extract rare earth elements out of the ore from
the Bear Lodge property. This highlights the unique refining methods employed at individual rare earth element
deposits. High grade ores (>2.5%) recovered from carbonatite dikes will first be processed at the Bear Lodge
property. Physical, on site, processing will include crushing and screening with water to mitigate dust 
pollution
.
Such processes are designed to concentrate the rare earth element bearing minerals and will overall resemble a
gravel or mill operation. The low-grade ore (<2.5%) mined out of the pit will be stockpiled for future processing
(Pickarts, 2011).
After the high grade ores are milled at the physical processing plant, they will be transported by truck to
Upton Wyoming. Upton, which is about forty miles away from the Bear Lodge property, was chosen because it
is an industrial park in close proximity to a viable railway and has existing infrastructure. The refining process
about to be explained is simply proposed. Rare Element Resources is currently developing their pilot plant. At
the Upton hydro-processing plant, the milled ores will be leached in four individual vats of heated 15%
hydrochloric acid creating a rare earth element oxide slurry. Soda ash or caustic soda will be introduced into the
slurry to raise the pH to 3. This precipitates the iron and hydroxides out of solution while keeping the rare earth
elements in solution. Other wastes including low levels of thorium, uranium, and metals will also be contained
in this iron hydroxide precipitate and will be disposed in a lined tailings facility. The pH of the remaining
solution will then be further raised to around 6.5 in order to precipitate a rare earth element bearing carbonate
for 90% rare earth element recovery. The carbonate bearing rare earth elements will be shipped to another
refinery to separate the individual rare earth elements. Rare Element Resources plans to work within the
boundaries of Nuclear Regulatory Commission (NRC) rules for construction of a tailing impoundment to
properly dispose of their wastes in case thorium and uranium become concentrated enough to warrant regulation
by the NRC (Pickarts, 2011).
5.0 Geochemistry and Possible Contaminants
Historical mining activities in the American West have created hundreds of thousands of environmental
disturbances. Mining activities expose previously unexposed rocks to bacteria, oxygen, water, and wind. The
summations of these weathering forces chemically and physically alter contaminant laden rocks that have been
below the surface for millions of years (EPA, 1995). Chemical and physical alteration of natural constituents in
rocks during mining can lead to environmental contamination; however, mining and milling itself is not the
only means of contaminating the environment. Refining processes that accompany hardrock mining represent
the same, if not worse, danger to the environment. While mining exposes contaminant laden rocks and increases
the surface area of minerals, refining isolates and concentrates wastes. The chemicals and compounds used
during refining could contaminate the environment too. Extreme care must be used in handling all the materials
associated with rare earth element production to ensure they are not released into the environment. This section
will introduce the possible contaminants from rare earth element production and the likely wastestreams of the
possible contaminants.
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One contaminant associated with rare earth element ores are radionuclides. Rare earth element bearing
minerals such as monazite, xenotime, and bastnasite can contain low levels of primordial thorium-232,
uranium-238, and their decay products. Uranium-235 is also present but in very low quantities. Thorium-232
and uranium-238 are rather benign, but some of the decay products can represent a danger to the environment
due to the energetic particles and gamma rays released during radioactive decay. For example in the uranium-
238 decay chain, bismuth-214 has a very energetic gamma release and produces radon-222 that can be inhaled
and decay in the lungs (Argonne National Laboratory, 2005).
Radioactivity is not the only concern from rare earth element production. As many as 17 different rare
earth elements could make their way into the environment during production from carbonate mineral
dissolution. The trivalent charge of the rare earth elements makes it difficult for them to bond with natural
compounds and come out of the environment. The toxicity of rare earth elements in the environment are not
completely understood but are considered metals at their elemental level.
The overall metal content of rare earth element ores is another geochemical concern associated with rare
earth element production. It is important to note rare earth element mining is hardrock mining, so any of the
metal concerns associated with hardrock mining should be a concern with rare earth element mining as well.
Metals such as aluminum, arsenic, cadmium, cobalt, copper, gold, iron, lead, manganese, silver, and zinc are
often associated with hardrock mining. The dangers of metals in the environment are well documented. Metals
of special concern at rare earth element mines include, but are not limited to, aluminum, arsenic, barium,
beryllium, cadmium, copper, lead, manganese, and zinc. Each of these metals have negative impacts on the
environment and may be found or present in elevated concentrations within rare earth element bearing minerals.
Many of the potential metal contaminants reside within sulfide minerals that often accompany rare earth
element ores. The dissolution of sulfide minerals, such as pyrite and chalcopyrite, can release these metals into
the environment.
Sulfide mineral dissolution also creates a reaction where sulfuric acid is formed and causes acid mine
drainage. Even if a mining company plans for a zero discharge mine, it is still important to analyze the possible
concerns in case discharge occurs. Sulfuric acid lowers the pH of water resources aiding in further sulfide
mineral dissolution, releasing more metals and acid into the environment. It represents a positive feedback loop
that could affect the environment. However, one positive aspect associated with rare earth element ores is that
sulfide minerals are usually not the main mineral constituents. Carbonate minerals are often the dominant
minerals present in rare earth element ores, especially in Region 8. These minerals provide a natural buffer to
acid generation and help neutralize acid generated during sulfide mineral dissolution. The dissolution of
carbonate minerals can raise pH of a water system too. This serves to slow sulfide mineral dissolution, which
helps prevent acid generation and the introduction of metals into water.
It is important to note the natural buffer of carbonate minerals in rare earth element ores can cause
potential environmental concerns as well. Too much carbonate mineral dissolution represents just as much
danger as sulfide mineral dissolution. Carbonate mineral dissolution introduces alkaline materials into water,
where they can raise the pH of water to elevated levels. The dissolution of carbonate minerals can also
introduce possible contaminants into the environment similar to how sulfide mineral dissolution can. Bastnasite
is one of the carbonate minerals that can undergo dissolution. The dissolution of this carbonate mineral is what
would release the rare earth elements into the environment. Another contaminant to be concerned about in
carbonate mineral dissolution is fluorine. Fluorine is also a constituent of rare earth element bearing bastnasite.
The dangers of fluorine in the environment are well documented. One last geochemical consideration associated
with rare earth element ore is the presence of the mineral riebeckite. Some rare earth element deposits contain
known occurrences of this asbestos mineral while others do not. This highlights the chemical uniqueness of
every rare earth element deposit and the importance of extensive chemical analysis in determining
environmental concerns at individual deposits.
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The radionuclides, rare earth elements, metals, sulfides, carbonates, and other possible contaminants
may be released into the environment at the mine site and refinery. The locations where the possible
contaminants could be introduced into the environment represent likely "wastestreams." All possible
contaminants discussed, if they exist at a mine, will be exposed in the bottom and walls of an open pit, where
they will interact with bacteria, oxygen, water, and wind. The possible contaminants will be exposed to these
weathering conditions over the life of the mine. The longer the pit remains open, the more these possible
contaminants can be released into the environment. The same can be said for the possible contaminants residing
in wasterock piles at a mine site. In fact, it is more likely the possible contaminants from wasterock piles will be
introduced into the environment considering these possible contaminants are not contained in a pit and only
man-made barriers can prevent possible contaminants from being introduced into the environment. The mill
itself represents a wastestream. Some rare earth element ores may unintentionally be lost during the milling
process where they will collect outside the mill. Also, intentional wastes will be piled on-site. Unless the ores
and wastes are carefully collected and monitored, contaminants could be easily introduced into the environment.
The possible contaminants can be found in the rare earth element products, byproducts, and waste
materials (Castor and Hedrick, 2006). This makes the handling of materials associated with rare earth element
production of utmost concern. Extreme care should be used to ensure the isolated and concentrated possible
contaminants are not released into the environment. All of the materials produced from the refining process will
have their respective holding piles. Each represents a likely wastestream. The chemicals and compounds used to
isolate and concentrate possible contaminants should be of concern too. Various acids and bases are used to
refine the rare earth element ores into marketable products.
6.0 Potential Risks to Human Health and the Environment
Mining, and the industries it supports, are among the building blocks of modern society. The benefits of
mining to the United States have been many, but they come at great cost to the environment. Over the past
century, there has been an increasing recognition that environmental protection is fundamental to a prosperous
economy and healthy society. As mines have increased in size and complexity, environmental controls have
become increasingly sophisticated. Modern mines are required to comprehensively evaluate environmental
concerns at the earliest stages of mine planning and design. Environmental controls are now considered as an
integral part of overall mine management (EPA, 1997). However, mining and refining of rare earth elements, if
not carefully monitored, can pose threats to human health and the environment. Nowhere is this more apparent
than in the nation dominating rare earth element production today.
6.1 China
According to the Chinese Society of Rare Earths, every ton of rare earth elements produced generates
approximately 8.5 kilograms of fluorine and 13 kilograms of flue dust. Additionally, sulfuric acid refining
techniques used to produce one ton of rare earth elements generates 9,600 to 12,000 cubic meters of gas laden
with flue dust concentrate, hydrofluoric acid, sulfur dioxide, and sulfuric acid. Not only are large quantities of
harmful gas produced, alarming amounts of liquid and solid waste also resulted from Chinese refining
processes. They estimate at the completion of refining one ton of rare earth elements, approximately 75 cubic
meters of acidic waste water and about one ton of radioactive waste residue are produced. The IAGS reports
China produced over 130,000 metric tons of rare earth elements in 2008 alone (IAGS, 2010). Extrapolation of
the waste generation estimates over total production yields extreme amounts of waste. With little environmental
regulation, stories of environmental pollution and human sickness remain frequent in areas near Chinese rare
earth element production facilities (Figure 21). United States government agencies, including EPA, can learn a
lot from China's environmental issues related to rare earth element production.
As discussed, mining and refining processes can introduce radionuclides, rare earth elements, metals,
and other potential contaminants into the environment at unnaturally high rates. Once introduced into the
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environment, the potential contaminants can be redistributed through the three "environmental mediums."
These three mediums include air, soil, and water. Living organisms depend on environmental mediums with
stable chemical properties for their survival. The release of the possible contaminants from rare earth element
production could alter the properties of the three environmental mediums. The upcoming sections will discuss
how the possible contaminants could be found in the environment and toxicology of the possible contaminants
to organisms.
6.2 Radionuclides
Uranium-238, thorium-232, and their decay products could present a threat to human health and the
environment. Radium-226 in the uranium-238 decay chain produces radon-222 gas and bismuth-214, which are
dangerous radionuclides (Argonne National Laboratory, 2005). Due to the short half-lives of radon-222 and
bismuth-214 from the radioactive decay of radium-226, these isotopes exhibit accelerated decay rates releasing
energetic particles and rays in shorter time spans than other radioactive isotopes. This explains why radium-226
is often regulated as opposed to uranium-238 (Duraski, 2011). The energetic particles and rays from radioactive
decay could represent a threat to human health and the environment as well. The energetic particles are
essentially small fast moving pieces of atoms, while the energetic rays are a form of electromagnetic radiation.
The energetic nature of these radioactive byproducts makes them dangerous. They have the potential to dislodge
electrons from important biological molecules including water, protein, and DNA.
Ores containing uranium-238 and thorium-232 are very mobile as dust resulting in air and soil
contamination, where radon-222 gas is constantly released (Argonne National Laboratory, 2005). Radionuclides
released into the atmosphere can be carried by wind and travel long distances before settling in soil or water.
Uranium is very soluble in water and radium, although less soluble, can also result in groundwater
contamination. Thorium is generally insoluble and seldom a groundwater concern (Duraski, 2011). The
radioactive materials reaching the ground can become incorporated by plants, which can then bioaccumulate in
organisms eating plants, including humans. Various studies have shown low doses of radiation causes humans
no harm, but massive amounts of ionizing radiation can cause detrimental health effects. Ionizing radiation from
radioactive decay is known to be a human carcinogen. The decay products of radon-222 gas in air represent the
greatest risk to developing cancer. The energetic particles can be inhaled and harm lung tissue to the extent
cancerous cells can develop. These carcinogenic effects can be observed in all living organisms.
6.3 Rare Earth Elements
The threats to human health and the environment from radionuclides are well know, but the threats from
rare earth elements are equally unknown. The movement of rare earth elements in the environment is generally
lacking. The toxicology of rare earth elements to aquatic, human, and other terrestrial organisms is not well
understood either. The toxicological effects would largely depend on the rare earth element compound and the
dose of that compound.
6.4 Metals
Carbonate and sulfide minerals associated with rare earth element ores contain a host of other metals and
metalloids (metals)in their crystal structure including aluminum, arsenic, barium, beryllium, cadmium, cobalt,
copper, lead, manganese, and zinc. This list constitutes the metals of greatest concern to environmental
contamination and organism health at rare earth element mines and refineries. These metals tend to adsorb to
clays and organic matter in soils. Despite this characteristic, metals dissolution is pH dependant. They are very
mobile at the right conditions in the environment, where they are often redistributed between air, soil, and
water. This makes metals a contaminant concern at rare earth element production sites in all three
environmental mediums as well as a toxicological concern for organisms depending on those mediums for
survival. Metals cannot be destroyed in the environment and only change forms. The form of the metals dictates
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the severity of the toxicological affects in organisms. The dose of the compound is important as well.
Discussions of why each individual metal is likely to be present within rare earth element ores, what mediums
they likely to be found, and the toxicology of them to organisms will now be presented.
Aluminum is the most abundant metal and overall the third most abundant element in the Earth's crust.
This makes aluminum widely distributed in rocks and tends to be a very reactive element in nature. Nearly all
aluminum is found combined with other elements, which often include oxygen, silicone, and fluorine. These
chemical compounds are commonly found in minerals and soils; however, small amounts of aluminum are
found dissolved as ions in water and attached to very small dust particles in air. Most aluminum compounds do
not dissolve in water unless the water is acidic or very alkaline (ATSDR, 2006). Considering aluminum can be
found in all three environmental mediums, it represents a possible threat to many different life forms. Aquatic
organisms are the most sensitive to aluminum toxicity with fish experiencing the greatest affects. Low doses of
aluminum cause no harm in humans, but high levels of aluminum have been shown to cause pulmonary effects
and possible developmental problems in children. Despite an abundance of aluminum compounds residing in
soils, these compounds do not pose much of a threat to plants because they do not take aluminum into their
systems (EPA, 2008).
Arsenic is widely distributed throughout the Earth's crust and commonly associated with economic
mineral ores. It is often combined with other elements in the environment such as oxygen, chlorine, and sulfur.
The arsenic compounds are found in soils and can make their way into air and water as well. Arsenic present in
air may travel long distances before settling in soil or water. Despite arsenic's mobility in the water, most
arsenic compounds remain in soil (ATSDR, 2007). The fact arsenic can be found in all three environmental
mediums make it a health risk to humans and other organisms. Arsenic has been known to be a human toxin
since ancient times. The Department of Health and Human Services (DHHS), EPA, and International Agency
for Research on Cancer (IARC) have classified arsenic as a human carcinogen (ASTDR, 2007). Increases of
skin cancer have been directly observed due to arsenic exposure. Chronic exposure of arsenic can also lead to
fatigue, gastrointestinal discomfort, blood disorders, and neuropathy in humans. Ingesting very high levels of
arsenic can even result in death. Low levels of arsenic can cause nausea, decrease production of white blood
cells, and affect heart rhythm. Mammals display the same general health effects from arsenic exposure. Arsenic
not only increases cancer rates in humans and mammals; it also causes cancer in aquatic organisms. Genetic
mutations can result where the growth and development of aquatic organisms is inhibited. Arsenic in plants has
been shown to cause wilting, dehydration, and death (EPA, 2008).
Barium is not high on the list of most abundant elements in the Earth's crust, but it is likely to be present
in elevated concentrations at rare earth element mines considering barium has a 3+ charge like the rare earth
elements. Barium should be considered a potential threat associated with rare earth element production because
of the barium content in rare earth element bearing minerals and the adverse health effects barium has on
mammals. Barium is relatively insoluble and typically not present in water, but barium compounds have been
known to exist in groundwater near waste sites. Large amounts of soluble barium compounds, such as barium
chloride and barium sulfide, in water can cause harmful muscular effects in humans, including changes in heart
rhythm and even paralysis. The human kidney also shows sensitivity towards chronic ingestion of soluble
barium compounds. Smaller amounts of barium ingestion in humans can result in gastrointestinal irritation
(ASTDR, 2007). Barium toxicity in aquatic and other terrestrial organisms is not well understood (EPA, 2008).
Beryllium is naturally occurring in rocks and could be found in elevated concentrations at rare earth
element mines because beryllium has a 2+ charge like calcium. Calcium is a chemical constituent of carbonate
minerals that characterize carbonatites. Beryllium can make its way into air, water, and soil. In air, beryllium
exists as very small particles that get carried by wind. Solubility of beryllium in water is dependent on the
compound. Some beryllium compounds are soluble while others are not. Weathering processes can change
insoluble compounds into soluble ones as well. A majority of beryllium compounds do not dissolve in water
and remain bound to soils, where they can reside for thousands of years without moving into groundwater.
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Water soluble beryllium compounds pose more of threat to organisms than insoluble forms, however the
greatest threat to humans from beryllium is in air. Inhalation of beryllium can harm the lungs of humans and
other terrestrial animals. Such damage is similar to pneumonia with reddening and swelling of the lungs. This
condition is referred to as "acute beryllium disease." Lung damage stemming from beryllium inhalation can
increase a person's risk of lung cancer. The DHHS and IARC have determined beryllium to be a human
carcinogen, while EPA believes beryllium is a probable carcinogen (ASTDR, 2002).
Copper is a natural constituent of rocks and often present in elevated concentrations in carbonatite. Low
levels can be measured in all air, soil, and water; therefore, copper is widespread in the environment. Copper
strongly absorbs to organic matter and other components of soil. If copper is released from the organic matter
and soil, it will not travel far in the environment before re-bonding and has little chance of reaching
groundwater sources. Copper that does dissolve in water can be carried in the form of copper compounds, free
copper, or attached to particles in suspension (ATSDR, 2004). Aquatic organisms are very sensitive to chronic
copper exposure, which can ultimately result in death. Plants and animals depend on copper as a micronutrient
vital to good health; however at elevated levels, copper becomes a toxic substance. Copper slows the growth
and development in terrestrial organisms (EPA, 2008). Humans can be negatively affected by copper too.
Breathing high levels of copper can cause irritation of your nose and throat. Ingesting high levels of copper can
cause nausea, vomiting, and diarrhea. Very-high doses of copper can cause damage to your liver and kidneys, as
well as cause death. It is uncertain whether copper is carcinogenic. EPA does not classify copper as a human
carcinogen, but further research identifying the cancer causing potential of copper is needed (ATSDR, 2004).
Lead is a naturally occurring metal in the environment and commonly present in small concentrations
within hardrocks. It binds strongly with soil particles where it may reside for years. Small amounts of lead can
make their way into water and travel into streams. This is more pronounced on acidic or very basic landscapes.
If introduced into solution, the lead will eventually bind strongly to sediments. Concentrations of lead in soils
can build to the extent it is taken up by plants. With elevated lead levels in soil, plants showed a decrease in
growth, photosynthesis, and water absorption (EPA, 2008). Lead is also known to exist in the air floating as tiny
particles. Although the effects of lead exposure are a concern for all humans, children under the age of seven
are most at risk. The health effects of lead in humans are the same whether inhaled or ingested. Lead toxicity
negatively impacts the cardiovascular, endocrine, muscular, nervous, reproductive, and respiratory systems and
may ultimately result in death. No conclusive evidence suggests lead is a human carcinogen, but the DHHS,
IARC, and EPA agree lead is a probable human carcinogen (ATSDR, 2007). Birds, fish, and mammals display
similar health effects as humans from lead exposure (EPA, 2008).
Manganese is a natural constituent of hardrocks that is known to be mobile moving between the three
environmental mediums. The type of soil and manganese compound determines the rate at which manganese
travels in the soil column. Manganese in solution tends to attach to particles floating in solution and settle into
the sediment. At low levels, manganese is considered a trace element essential to maintaining health in humans
and other mammals (ATSDR, 2008). However, too much manganese has been shown to impair
neurobehavioral, muscular, and gastrointestinal function. Manganese is vital for normal physiologic functioning
in all animal species. Several disease states in humans have been associated with both deficiencies and excess
intakes of manganese. The EPA concluded not enough scientific information exists to determine if manganese
is a human carcinogen (ATSDR, 2008). Manganese toxicity towards aquatic and terrestrial organisms is
generally lacking.
Zinc is released from hardrock sources and found naturally in air, soil, and water. It is labeled as an
essential element to many different organisms, where too little zinc can cause as much health problems as too
much zinc intake. The concern is that elevated zinc concentrations could be released into the environment
making zinc harmful rather than helpful (ATSDR, 2005). Toxic amounts of zinc in water have resulted in
reduction of growth and reproduction rates of aquatic plants and animals with increased mortality rates of both
groups. Elevated levels of zinc in mammals can cause health problems too. Cardiovascular and nervous systems
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can be negatively affected. At high levels, zinc has caused liver and kidney problems in humans that are then
amplified by hematological affects (EPA, 2008).
6.5 Mountain Pass Legacy
The Mountain Pass mine and refinery began operation in 1952, when historically few environmental
controls existed. Due to lower rare earth element prices and competition from China, mining at Mountain Pass
halted in the mid 1980's (Castor and Hedrick, 2006). The site contains an open-pit mine, overburden stockpiles,
a crusher and mill/flotation plant, a separation plant, a mineral recovery plant tailings storage area, on-site
evaporation ponds, and off-site evaporation ponds, as well as laboratory facilities to support research and
development activities, offices, warehouses and support buildings (Figure 22). Groundwater and soil
contamination is known to exist around the facility. Contaminants include barium, gross alpha, gross beta,
nitrate, sodium lignin sulfonate, strontium, total dissolved solids, total lanthanides, total petroleum
hydrocarbons (kerosene/diesel), total radium, total thorium, and total uranium. Claims have been brought under
environmental laws, regulations, and permits for toxic torts, natural resource damages and other liabilities, as
well as for the investigation and remediation of soil, surface water, groundwater and other environmental media
(Environmental Audit, 2010).
On September 30, 2008, Molycorp Minerals LLC acquired the Mountain Pass, California rare earth
deposit and associated assets from Chevron Mining Inc. through Rare Earth Acquisitions LLC (which was later
renamed Molycorp Minerals, LLC). The mine and refinery at Mountain Pass will reopen in 2012 after
modernization to its production facilities are completed. Molycorp proposes to expand the open-pit mine both
laterally to the west, southwest and north as well as deepening it. In addition to the existing overburden
stockpile located west of the pit, which will serve as the initial overburden stockpile when mining
recommences, additional overburden stockpiles will be constructed to the north or east of the pit to provide
additional storage capacity sufficient to accommodate the remaining overburden material for the existing
permitted life of the mine. New facilities, including the construction of a control lab, additional warehousing
and raw material storage facilities, and a new mill are proposed in the modernization and expansion project
(Environmental Audit, 2010).
6.6 Bear Lodge Case Study
The Bear Lodge and Mountain Pass properties exhibit somewhat similar geology and contain the same
dominant rare earth element bearing mineral, bastnasite. Analyzing the environmental issues associated with
rare earth element production at Mountain Pass provides the model for identifying potential risks at the Bear
Lodge property. Any of the environmental concerns at Mountain Pass should be a concern at the Bear Lodge
property along with some unique concerns specific to the Bear Lodge property. Some of possible contaminants
associated with mining at Bear Lodge include, but are not limited to, radionuclides, rare earth elements, metals,
sulfides, carbonates, and other elements such as fluorine.
Water represents the environmental medium of overall greatest concern at Bear Lodge. Not only can the
possible contaminants go into solution, a great deal of water is consumed during rare earth element mining and
processing. Such issues generate both water quality and quantity concerns that will heavily depend on what
management practices are put into place. Pit lake water represents a potential environmental concern, however
Rare Element Resources does not intend for a pit lake to develop because the pit will be above the water table
and surface water will be diverted away from the pit. Even though the company is taking these measures, the
environmental concerns of pit lake water must be analyzed because it remains a possibility until the mine is
opened and proven not to be an issue. This could be the most dangerous water issue at the mine if the pit is
opened to depths where sulfide minerals are present considering the constant contact water would have with
sulfides at depth. Water will also be in constant contact with carbonate minerals in the carbonatite dikes.
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Meteoric water will come into contact with stockpiled rare earth ores while being saved for future
production. Depending on how much ore is piled, how long they remain piled, and what management practices
are put in place will determine the extent of contaminant release into the environment. To prevent
contamination from these likely wastestreams, the runoff needs to be captured and stormwater controls put in
place. The waters produced from the physical processing plant may pose an environmental threat as well
(Kozel, 2011).
The hydrology of the Bear Lodge area is not well understood. However, the Madison formation remains
the prominent aquifer in the region that is often hundreds of feet from the surface (Wyoming State Geological
Survey, 2008). The Bear Lodge area is a recharge zone for the regional aquifer responsible for providing
drinking water to people in Sundance and the surrounding areas of northeastern Wyoming and western South
Dakota. According the National Oceanic and Atmospheric Administration, northeastern Wyoming receives on
the order of 15-20 inches of rain every year. The streams in the area are predominantly ephemeral with some
surface springs present (Timm, 2011). The lack of surface water leaves no choice but for Rare Element
Resources to use water from the Madison formation in rare earth element production at the property. Rare
Element Resources believes the aquifer can handle the company's planned water extraction, but it is not clear
how aquifer usage will affect surface spring behavior at the Bear Lodge property (Pickarts, 2011). These springs
provide the most reliable water source for animals in the area. Elevated water extraction from the Madison
could dry the springs or they may not be affected. Rare Element Resources plans to recycle 100% of water used
during physical processing and collect runoff from tailings piles to be used at the mill. Such a strategy may
address some of the water quality and quantity issues at Bear Lodge and could prevent the Madison aquifer
from overuse.
Surface waters at the Bear Lodge property need to be protected since the proposed mine location resides
at the headwaters of Beaver Creek, which eventually flows into Cook Lake. This is a popular recreation area for
locals who value being able to use the water resource at their leisure. The contaminants from the Beaver Creek
headwaters could make their way to Cook Lake affecting the water quality. Rare Element Resources
understands the risks to ground and surface waters in the area and employs of the services of Knight Piesold
consulting in matters related to environmental monitoring. An immense database of background data of the
surface and ground waters in the Bear Lodge area exists because of previous exploration and monitoring of the
atomic power station nearby. Knight Piesold is also actively taking water samples on site to better understand
the natural environment and gauge how future mining affects the area. A total of 14 ground water monitoring
wells are established on the property. There will also be two piezometers in the mining pit once it is opened.
Currently, surface waters are being tested monthly, while the ground water wells are tested quarterly (Pickarts,
2011).
Water is a dominant concern at most mine sites, not just at the Bear Lodge property. Rare earth element
mining presents various water issues of concerns. Specific concerns include contamination of groundwater,
surface water, and surface water run-off. Most of these concerns result from the chemical constituents of the
rare earth element ores. Oxidation and dissolution of these constituents have the potential to release
contaminants and cause environmental hazards. Such processes are accelerated by increasing the surface area of
the rock by crushing, milling, and processing. This is especially true in rare earth element ores that often contain
greater amounts of minerals that can undergo dissolution. Rare Element Resources and the USES office in
Sundance do not anticipate any acid drainage issues at the Bear Lodge property, but acid mine drainage is a
concern at many mine sites and needs to be monitored for the long-term at the Bear Lodge property.
Additionally, the natural buffer in the carbonatite may help mitigate acid concerns. The natural buffer in
carbonatite also explains why Rare Element Resources will leave at least a 30 foot reaction front directly above
the sulfide rich zone. The reaction front ensures enough carbonate is present to prevent an acid lake from
forming in the pit (Pickarts, 2011).
image:
20
Air quality issues associated with mining and processing are of concern too. Dust can be created during
physical processing, and fumes can be generated from chemical processing. This is certainly the case at the
Bear Lodge property and Upton processing plant. The mining and milling processes at Bear Lodge may also
cause deposition of particulates off-site if proper precautions are not put in place. The collection of organic and
inorganic particles that make up dust have the potential to harm human health and the environment. Airborne
radionuclides represent an air quality concern at the Bear Lodge property. Alarming concentrations of
radionuclides are not known to exist at Bear Lodge, but the physical processing of rare earth ores onsite could
cause radionuclides present in the ore to become airborne. This is why Rare Element Resources will use water
to ensure excess dust is not created during the crushing and grinding of rare earth ores. Knight Piesold has also
established four air monitoring stations around the property to record possible airborne radionuclide (Pickarts,
2011). The fumes bound to be created by chemical refining of the rare earth element ores will need to be
addressed as well. Radionuclides could be released into the atmosphere near Upton Wyoming. Metals and other
elements such as have the potential to be released into the air as well. Rare Element Resources will need an air
permit in compliance with the clean air act.
Another important oversight of mining is to ensure soil quality and quantity is maintained during and
after mining occurs. Possible contaminants of the rare earth ore, such as radionuclides, metals, and rare earth
elements, can become incorporated into the soils as a result of weathering or during rare earth element
production. Metals, rare earth elements, and radionuclides can come out solution and precipitate in soils. The
contaminants can reside in the soils for extended time periods depending on weathering and future land use.
Contamination at Bear Lodge has yet to be seen. A robust monitoring program and well designed production
plan at the Bear Lodge property and Upton chemical processing plant should prevent, or at least address, any
problems caused by the possible contaminants and environmental concerns discussed.
7.0 Conclusions
Attention towards rare earth elements, including key and critical elements, will only grow as
governments around the world scramble to address serious supply issues as a result of increased global usage
and decreased export quotas of rare earth elements by China over the past few years. The United States
government is concerned about rare earth element supply considering the elements are vital to electronic, clean
energy, and military technology production. Each sector either directly influences the U.S. economy or national
defense. The USDOE conducted a study to determine which periodic elements are essential to maintaining the
integrity of the United States where key and critical materials were identified. Nine of the 14 key elements are
rare earth elements. The rare earth elements receiving key designation include lanthanum, cerium,
praseodymium, neodymium, samarium, europium, terbium, dysprosium, and yttrium. The five other key
elements are elements scattered throughout the periodic table and include lithium, cobalt, gallium, indium, and
tellurium. Critical elements describe key elements that are necessary for clean energy technology production
and have even greater supply risks than the key elements. The key elements receiving critical designation in the
short term (0-5 years) were dysprosium, neodymium, terbium, europium, yttrium, and indium. Critical materials
in medium term (6-15 years) include dysprosium, neodymium, terbium, europium, and yttrium. All are rare
earth elements. The same USDOE report has even outlined a strategic plan to explore substitution of key and
critical elements in future technologies, recycling from waste electronics, and developing a globally diverse
supply of these elements.
Record high rare earth element prices have already resulted in increased investments for exploration
and development of rare earth element deposits in the United States. Companies are rediscovering the mining
potential of rare earth element deposits across the nation from the Bokan Mountains in Alaska to the Bear
Lodge Mountains in Wyoming. Favorable market conditions and a promising deposit could put a Region 8
state at the center of rare earth element mining. The realization of rare earth element production in Region 8 is
real and fast approaching. Within five years, Rare Element Resources plans to have the second operating rare
image:
21
earth mine in United States at the Bear Lodge property. This northeastern Wyoming deposit has the potential to
become the largest producer of rare earth elements in America.
As with any mine or refinery, rare earth element production could contaminate the environment if best
management practices are not used and the operation is not closely monitored. Federal and state agencies must
determine how to best oversee the Bear Lodge project to ensure this operation does not put human health and
the environment at risk. Many potential contaminants reside within rare earth element bearing rocks and
minerals. The possible contaminants include, but are not limited to, radionuclides, rare earth elements, metals
such as barium, beryllium, copper, lead, manganese, and zinc, sulfide minerals, carbonate minerals, and other
potential contaminants such as fluorine and asbestos minerals. Mining exposes these possible contaminants,
while refining isolates and concentrates the possible contaminants. Rare earth element mining is hardrock
mining, so any of the environmental concerns associated with hardrock mining could be a concern with rare
earth element production.
The possible contaminants cause negative effects towards aquatic and terrestrial organisms in addition to
humans. Some of the radionuclides and metals contaminants are even classified as human carcinogens by
international and federal health agencies. Others possible contaminants increase the mortality rates of aquatic
and terrestrial organisms. Cooperation between all government agencies designed to protect the environment
and companies responsible for rare earth element production will prove invaluable in ensuring these operations
do not pose a threat to human health and the environment in the United States. Even though mining at the Bear
Lodge property is early in the planning stages, cooperation and communication between Rare Element
Resources, Wyoming Department of Environmental Quality (WDEQ), and USES seem strong. Areas of China
have suffered the consequences of haphazard rare earth element production. The stronger the communication
lines between the different parties, the better off the surrounding environment and human population will be.
image:
22
8.0 References
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Aluminum." September 2006.
15 July 2011 <http://www.atsdr.cdc.gov/toxprofiles/tp22-cl-b.pdf>.
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Arsenic ." August 2007. 15
July 2011 <http://www.atsdr.cdc.gov/ToxProfiles/tp2-cl-b.pdf>.
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Barium." August 2007. 15
July 2011 <http://www.atsdr.cdc.gov/ToxProfiles/tp24-cl-b.pdf>.
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Beryllium." September 2002.
15 July 2011 <http://www.atsdr.cdc.gov/ToxProfiles/tp4-cl-b.pdf>.
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Copper." September 2004. 15
July 2011 <http://www.atsdr.cdc.gov/ToxProfiles/tpl32-cl-b.pdf>.
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Manganese." September
2008. 15 July 2011 <http://www.atsdr.cdc.gov/ToxProfiles/tpl51-cl-b.pdf>.
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Zinc." August 2005. 15 July
2011 <http://www.atsdr.cdc.gov/ToxProfiles/tp60-cl-b.pdf>.
Agency for Toxic Substances and Disease Registry. "Public Health Statement: Lead." August 2007. 15 July
2011 <http://www.atsdr.cdc.gov/ToxProfiles/tpl3-cl-b.pdf>.
Armbrustmacher, T. "Geology and resources of thorium and associated elements in the Wet Mountains area,
Fremont and Custer Counties, Colorado." United States Geological Survey Professional Paper 1049-F. 1988.
Armbrustmacher, T. "The complex of alkaline rocks at Iron Hill, Powderhorn district, Gunnison County,
Colorado." Gunnison Gold Belt and Powderhorn Carbonatite Field Trip Guidebook. Denver Region Exploration
Geologists Society, 1983. 28-31.
Hedrick, J. and Castor, S. "Rare Earth Elements." Industrial Minerals Volume 7. 2006. 769-792.
Hurst, C. China's Rare Earth Elements Industry: What can the West learn? Washington: Institute for the
Analysis of Global Security, 2010.
Kopera, J. Introduction to NiMH Battery Technology. 25 June 2004. 2 June 2011
<http://www.cobasys.com/pdf/tutorial/InsideNimhBattery/inside_nimh_battery_technology.html>.
Kozel, Steve. Bear Lodge Project USES Concerns Justin Paul. 30 June 2011.
Long, K., Van Gosen, B., Foley, N., and Cordier, D. "The Principle Rare Earth Element Deposits of the
United States: A Summary of Domestic Deposits and a Global Perspective." Unietd States Geological Survey
Scientific Investigations Report 5220. 2010.
McCulloch, Robin. Sheep Creek Project Overview Justin Paul. 30 June 2011.
image:
23
Olson, J., and Hedlund, D. "Alkalic rocks and resources of thorium and associated elements in the
Powderhorn district, Gunnison County, Colorado." United States Geological Survey Professional Paper 1049-C.
1981.
Pickarts, Jaye. Bear Lodge Project Overview Justin Paul. 22 June 2011.
Rare Earth Metals. 22 July 2011 <http://mineralprices.com/default.aspx>.
Rare Element Resources. 30 May 2011. Welcome to Rare Element Resources. 17 June 2011
<http://www.rareelementresources.com/i/pdf/RES_CorpProfile.pdf>.
Staatz, M., Armbrustmacher, T., Olson, J., Brownfield, I., Brock, M., Lemons, J., Coppa, L., and Clingan, B.
"Principal thorium resources in the United States." United States Geological Survey Circular 805. 1979.
Staaz, M. "Geology and description of the thorium-bearing veins, Lemhi Pass quadrangle, Idaho and
Montana." United States Geological Survey Bulletin 1351. 1972.
Staaz, M. "Geology and description of thorium and rare-earth deposits in the southern Bear Lodge
Mountains, northeastern Wyoming." United States Geological Survey Professional Paper 1049-D. 1983.
Timm, Jeanette. Bear Lodge Project USFS Concerns Justin Paul. 22 June 2011.
Tintina Resources. Welcome to Tintina Resources. 15 July 2011
<http://www.tintinaresources.com/Sheep_Creek_Project_opUSAcl_hy_Page.aspx>.
United States Department of Energy. "Critical Materials Strategy." 2010.
United States Environmental Protection Agency. "Ecological Toxcity Information." 19 May 2008. 15 July
2011 <http://www.epa.gov/R5Super/ecology/html/toxprofiles.htm>.
United States Environmental Protection Agency. "Hardrock Mining Framework." 1997.
United States Environmental Protection Agency. "Historic Hardrock Mining: The West's Toxic Legacy."
EPA 908-F-95-002. 1995.
Van Gosen, Bradley. Rare Earth Element Deposits in Region 8 Justin Paul. 30 June 2011.
Van Gosen, B., and Lowers, H. "Iron Hill (Powderhorn) carbonatite complex, Gunnison County, CO—A
potential source of several uncommon mineral resources." Mining Engineering v. 59, no. 10 (2007): 56-62.
Van Gosen, B., Gillerman, V., and Armbrustmacher, T. "Thorium deposits of the United States—Energy
resources for the future?" United States Geological Survey Circular 1336. 2009.
Wyoming State Geological Survey. "WWDC Green River Basin Water Plan II." 22 October 2008. Wyoming
State Water Plan. 19 July 2011 <http://waterplan.state.wy.us/plan/green/2010/finalrept/gw_toc.html>.
image:
24
9.0 Appendix
H
Li
Na
K
Rb
Cs
^^^^^m
Fr
Rare Earth
Be
Mg
Ca S
^^~H
Sr ^
Ba t.
Ra **
c Ti
r zr
JHf~
L. Rf
La C
V
Mb
Ta
Ob
0«
•
A*lirid*-i
Ac Th
Cr
Mo
W
Sg
Pr
Mn
Te
Re
Bh
Nd
Pa
U
El
b,
Fe
Ru
Os
H5
Pm
Np
e
f G<
Co
Rh
Ir
Mt
3m
Pu
n
ie
lagy.
Nl
Pd
Pt
Eu
Am
nts
ron
Cu
Ag
Au
Zn
Cd
Hg
3d
Cm
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
0
S
Se
Te
Po
Tb Dy Ho Er Tm
8k Cf Es Fm Md
Yt
Nc
F
Cl
Br
1
At
He
Me
Ar
Kr
X*
Rn
> Lu
^
Figure 1: Periodic table highlighting all 17 rare earth elements in orange. Figure adapted from geology.com.
EAVY Rare Earth Elements
H
Li
Na
K
Rb
•^•^H
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
LIGHT Rare Earth Elements
by GflQiogy cc-m
Sc
Y
IfU
Ac-Lr
Ti
Zr
Hf
Rf
V
Mb
Ta
Db
Cr
Mo
I^^^^M
W
Sg
Mn
Tc
^^^^^m
Re
Bh
Fe
Ru
Os
Hs
Co
Rh
Ir
Mt
Ni
Pd
Pt
Cu
Ag
^^^^^m
Au
Zn
Cd
^^m^^m
Hg
B
Al
Ga
In
Tl
C
Si
Ge
Sn
Pb
N
P
As
Sb
Bi
0
S
Se
Te
F
Gl
Br
1
Po At
He
Ne
Ar
Kr
Xe
Rn
•
Eu Gd Tb
Dy
Ho Er
Tm Yb
Lu]
Acllp dci-
Ac
Th
Pa U
Np
Pu
Am Cm Bk
Cf
E$ Fm
Md
No
Lr
Figure 2: Periodic table designating "light" and "heavy" rare earth elements. The periodic elements
highlighted in violet represent the "light" rare earth elements, while the orange highlight elements are "heavy"
rare earth elements. Figure adapted from geology.com.
image:
25
11
Na
19
K
37
Rb
4
Be
12
Mg
zo
Ca
33
Or
- Key material addressed in Slrategy
LJ-LfthJsm In-lrnSum Pr-Prasewtyrniunni Eu-£urap*tm
Y-Ylkium Ta-TtlliiMim Nd-NeocJyiiMjrr Tb-Teiblum
Co-Cobs! La-Urtiiarun Sm-Samariurn Dy-Qysproslum
Ga-Gallium Ce-Cenutn
13
Al
21
Sc
22
Ti
40
23
V
41
Mb
Cr
42
Mo
25
Mn
43
Tc
Z6
Fe
44
Ru
45
RJh
28
N
.16
47
30
Zn
48
Cd
14
Si
32
Qe
50
33
As
51
Ob
a
o
16
5
34
Se
•/
Cl
35
Br
2
He
10
18
Ai
36
Kr
54
He
55
Cs
56
Ba
T2
HI
n
Ta
75
Ra
76
Os
77
Ir
79
R
T9
Au
80
MB
61
TI
62
Pb
Bi
84
Po
A1
86
Rn
87
83
Ka
104
Rf
IDS
DC
106
107
Bh
10B
Hs
109
Ml
110
Os
111
112
Cn
113
Uut
114
Uuq
115
Uup
116
Uuh
117
Uus
118
Uuo
119
Uur
Lanthaoides
1 Actriides
Ac
iw
91
Pa
B2
U
61
Pm
Pu
Am
64
Gd
96
Cm
Bk
'Jt:
Cf
67
Ho
Es
68
Er
1UU
Fm
Tm
1U1
Md
70
¥b
No
71
Lu
1IW
lr
Figure 3: Periodic table with the 14 key materials described by the USDOE highlighted in blue. Figure adapted
from USDOE (2010) "Critical Materials Strategy" report.
Figure 4: Google Earth map showing the location ofMolycorp 's Mountain Pass mine.
image:
26
[1| Lynflj Corp, (I) MotywrpMmenl* (3}{4) Gwt Wwtem Mineral*, £f Alfcane R«sour«sr
govt/Toyota Tsustio/Sojltz, [7| Arafura ResDurces, |3) Avalon Rare Metals. (§) Kazatoniprom/SuniitomD,
110) Stans Energy, (HI Greenland Miner^fc and Energy, [12| Rare Element Re&oureei, [13) Pete Mountain
[14) Quest Hare Mhenk, (IS) Ueore- Uranium, (16) u£ few Earthi, (17) MatamecExptoratlons,
|IB) Etruscan Resources, [19) Montero Mining, [20| Tasman Metals, (21) Neo Material TechnolDgies/Mitsubiihi
Figure 5: World map labeling the prominent rare earth element deposits owned by mining companies. Figure
adapted from USDOE (2010) "Critical Materials Strategy" report.
image:
27
Salmon Bay, AK
Bokon Mtn, AK
Figure 6: Map with principle United States rare earth element deposits labeled. Figure adapted from United
States Geological Survey (2010) "Principle Rare Earth Elements Deposits of the United States-A Summary of
Domestic Deposits and a Global Perspective " report.
image:
28
Figure 7: Google Earth map showing the location of the Bear Lodge property.
Figure 8: Picture displaying a sample of carbonatite from Brazil.
image:
29
Figure 9: Photo of Bull Hill (center) taken during site visit June 22, 2011.
Jf
E J~' Ml :--„,
I—- -g— • ^V.:"i~~"r:"5;''^~--~r~"" •«!—5. ••
^ ' t •^^•".•r-LAVJJ"--"
i fll -:?> •
''
' -* i
-el
JP »*' • t* I • > ' ' I "•' I '".
Figure 10: Geologic cross-section constructed by Hecla Mining Company depicting the carbonatite dikes near
Bull Hill and the respective mineralogical zones. FMR zones are shown in red and the carbonatite-oxide zone is
represented by green. The dark blue area displays where the subsurface rocks have been oxidized and the
lighter area depicts where oxidation is beginning to happen. Figure adapted from Rare Element Resources
"Bear Lodge Summary " document.
image:
Figure 11: Image ofFMR core sample at Rare Element Resources core shed in Sundance Wyoming.
Photo was taken during site visit June 22, 2011.
Figure 12: Google Earth map displaying the Iron Hill deposit resides.
image:
Figure 13: Google Earth map showing where the Wet Mountains deposit is located.
' *
Quartz-barite-limonite-thoritHS vein Gneiss
irocrr
l
Figure 14: Photo of mineralized quartz veins at the Wet Mountains Deposit. Figure adapted from
United States Geological Survey (2010) "Principle Rare Earth Elements Deposits of the United States-A
Summary of Domestic Deposits and a Global Perspective " report.
image:
Figure 15: Google Earth map displaying where the Lemhi Pass deposit resides.
iu£*4.
*?•
-
-
• . ". V • •-. . ^A£ ™lpfr"/|
• ;
Figure 16: Photo of mineralized quartz veins at Lemhi Pass. Figure adapted from United States
Geological Survey (2010) "Principle Rare Earth Elements Deposits of the United States-A Summary of
Domestic Deposits and a Global Perspective " report.
image:
Figure 17: Google Earth map showing the location of the Sheep Creek project.
TD 240 m
w> tn
u^ wfl^w
W^
* - Historic Hole
** - Historic Results
UCZ - Upper Copper Zone
LCZ - Lower Copper Zone
Precajnbrian Metamorphics
w"* W»
^ \X* VA^ \^" ^
."' K.- ' ., ' ,,' ' ...•-•..-•-,,.-• :.-•• W ' ... -• ..-•' ... - ....'• .-.'• -,.•
n °.
200
Figure 18: Geologic cross-section at Sheep Creek property. Adapted from Tintina Resources' website.
image:
34
Figure 19: Photo ofMolycorp's Mountain Pass open-pit mine in southeastern California.
REE Process
High tech applications
Thare are hmfr e<H of
high teen appfcation! for
REE.
Floatation Process
Mineral cortahlng
REE ts ».lract»d
it iBnlnaisll*
Mona:lt«
i
Separation Process
REE Is separaitM
from mineral
Green energy
Hybrid electric vehicles
Water treatment
Defense
High tech
Diagram 1
Figure 20: Flowchart depicting the rare earth element refining process. Figure adapted from IAGS
(2010) report.
image:
Figure 21: Google Earth image of the Bayan Obo mine in China.
Figure 22: Google Earth image of Mountain Pass mine displaying the components of the mine, refinery,
and support buildings.
image:
